YF200 R1 – Yamaha YF200 R1 Engine Kit (Unassembled). The Yamaha YF200 R1 kit comes with a billet connecting rod, ARC billet aluminum adjustable flywheel, stainless steel valves, XR extreme duty valve springs, tubular chromolly push rods, custom 71mm racing piston, Tillotson carburettor, forged crankshaft and Cometic gaskets which incorporate the latest in technology. (Shown with Header and Chain Guard – Not Included)